The present invention relates to a method for manufacturing a capacitive operation device for use in the operation of an electronic device included in a vehicle or the like.
Traditionally, capacitive operation devices are known as operation devices for operating electronic devices. For example, JP 2009-111996A discloses a capacitive operation device including an operation panel including an operated portion operated by an operator and an electrode film disposed on the back surface of the operation panel. The electrode film includes a sensing electrode. The capacitance between the sensing electrode and the operated portion varies according to the distance between the sensing electrode and the operated portion. The electrode film is attached to the back surface of the operation panel with an adhesive in a state in which the sensing electrode overlaps the operated portion in a direction in which the operation panel and the electrode film are placed on top of each other.
At the time of manufacturing a capacitive operation device as described in JP 2009-111996A, or in other words, at the time of bonding the electrode film to the back surface of the operation panel, bubbles may be introduced therebetween. If the operated portion is operated when such bubbles are interposed between the sensing electrode and the operated portion, that operation may not be detected. Specifically, the distance between the sensing electrode and the operated portion when bubbles are interposed between the sensing electrode and the operated portion is greater than that when no bubble is interposed therebetween. Accordingly, in a state in which bubbles are interposed between the sensing electrode and the operated portion, the rate of change in the capacitance between the operated portion and the sensing electrode when the operated portion is operated is reduced. Consequently, the operation of the operated portion may not be detected accurately. Meanwhile, it is very difficult to prevent introduction of bubbles between the sensing electrode and the operated portion at the time of manufacturing such a capacitive operation device.